JPS6226729A - Relay driver - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to a relay drive device used in home appliances used in general households.

BACKGROUND ART In general, in relays having mechanical contacts, power loss due to contact resistance of relay contacts is sufficiently smaller than power loss due to on-resistance of semiconductor switching elements.
Suitable for switching high power loads. but,
Since the contacts deteriorate significantly due to arc discharge that occurs when the load current is switched on and off, there have been problems in terms of lifespan and reliability. As one method for solving this problem, a method has been proposed in which relay contacts are opened and closed at predetermined phases of the AC power supply voltage. In this method, the operating time from when the relay coil is energized until the contacts actually close, and the recovery time from when the energization is stopped until the contacts open are measured, and the relay is determined based on the time difference between these values and the cycle of the AC power supply. The phase of energization and de-energization of the coil is determined. Figure 4 is a diagram showing its operation, where waveform M is the AC power supply voltage waveform, waveform B is the synchronization signal of this power supply (Figure 4 shows an example of zero voltage synchronization), and waveforms C and D are the Driving signal waveform and opening/closing signal waveform when the relay contact is closed E and F show the driving signal waveform and opening/closing signal waveform when the relay contact is opened, respectively. T in Figure 4. n is the operating time, Toff is the return time, and the output phases P and P2 of the drive signal are determined from the time differences T1 and T2 between these times and the cycle T of the AC power source.

Problems to be Solved by the Invention However, in such conventional methods, control is performed based on the previous operating time and return time.
If the operating time and return time for each opening/closing change, it becomes difficult to control to a predetermined phase, and the contacts end up being worn out.

In particular, in the initial stage of driving, which is often used when driving a relay, as shown in Figure 2, a current higher than the current is passed through the relay coil, and after driving, to prevent the relay coil from generating heat, a driving power source is used that reduces the current. If this happens, the voltage applied to the relay coil will fluctuate, making the above problem more likely to occur.

As shown in FIG. 5, the operating time becomes shorter as the driving power supply voltage becomes higher, and the return time becomes longer.

The object of the present invention is to stabilize the operation by keeping the operating time and return time substantially constant each time the device is opened and closed.

Means for Solving the Problems In order to solve the above problems, the present invention provides a re-output prohibition means for prohibiting re-output of the drive signal for a predetermined period after the contact is driven, in the drive control section of the relay contact. 〇Function The present invention has the above-described configuration, and the driving conditions (
For example, since the drive power supply voltage and armature position can be made uniform, the operation time and return time for each opening and closing become approximately constant, and the operation of the drive device is stabilized.

EXAMPLE Hereinafter, an example of the present invention will be described based on the accompanying drawings. In FIG. 1, 1 is an AC power source, 2 is a load, 3 is a relay contact that opens and closes this load 2, 4 is a power synchronization signal generating means that generates a signal synchronized with the AC power frequency, and 5 is an opening and closing of the relay contact 3. This is an opening/closing phase detection means for detecting the phase. 6 is a relay coil 6a, a drive power source 6b, and a transistor ec.

This relay driving means includes a Zener diode 6d and resistors 6e and efi. Reference numeral 7 denotes a control section for controlling the relay driving means 6, and this control section 7 includes a time difference measuring means 8 for inputting the signals from the opening/closing phase detecting means 5 and the power synchronization signal generating means 4 and measuring the time difference therebetween; It has an output phase determining means 9 that determines the output phase of the drive signal of the relay contact 3 based on the time difference, and a re-output inhibiting means 1o that prohibits the re-output of the drive signal for a predetermined period after the output.

11 is a power supply for the control unit.

As shown in FIG. 2, except for the predetermined period (period sufficiently longer than t1 to t2 and t3 to t4 in FIG. 2) during which the re-output prohibition means 1o prohibits the output change, the output phase is determined. The output signal of the means 9 is directly applied to the relay driving means 6, and the relay contacts are opened and closed. However, as shown in FIG. 3, even if the output signal from the output phase determining means 9 is changed during the period in which the re-output inhibiting means 1o prohibits changing the output (the shaded area in FIG. 3), the relay is not driven. The signal applied to the means 6 is not changed and is only changed after a predetermined period of time has elapsed. (FIG. 3 t2) Therefore, the voltage that opens the relay contact is vOn in FIG. 2, and the voltage that closes it is voff, which is a constant value.

Effects of the Invention As described above, the relay drive device of the present invention prohibits re-output for a predetermined period after the relay drive output, so the operating time and recovery time of the relay are almost constant, ensuring that the predetermined output is achieved. The relay contacts can be opened and closed in the phase of This can improve reliability.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the device of the present invention, and FIG.
Figure 3 and Figure 3 are operating waveform diagrams, Figure 4 is an operating waveform diagram of a method in which the reel contact is opened and closed at a predetermined phase of the AC power supply voltage, and Figure 5 is the relationship between the operating time and return time and the drive power supply voltage. It is a characteristic diagram which shows an example. 1...AC power supply, 2...Load, 3...
,, = +7 single contact, 4...Power synchronization signal generation means, 5...Opening/closing phase detection means, 6...
... Relay driving means, 7... Control section, 8...
. . . Time difference measuring means, 9 . . . Output phase determining means, 10 . . . Re-output prohibition means. Name of agent: Patent attorney Toshio Nakao and 1 other person 2nd
Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] A power synchronization signal generation means for generating a signal synchronized with the AC power frequency, an opening/closing phase detection means for detecting the opening/closing phase of the relay contact, and a time difference for inputting the former power synchronization signal and the opening/closing phase respectively and measuring the time difference therebetween. a control section having a measuring means, an output phase determining means for determining the output phase of the drive signal of the relay contact based on the time difference, and a re-output prohibiting means for prohibiting the re-output of the drive signal for a predetermined period after the output;
and a relay drive means for opening and closing the relay contacts in response to a drive signal from the control section.